Combine cherries and cherry brandy in a small bowl. Let stand until cherries plump, about 20 minutes. Preheat oven to 350. Using melon baller, hollow center of each apple half. Arrange apples, cut side up, in glass baking dish. Fill centers with cherry mixture, dividing evenly. Combine brown sugar, maple syrup, and butter in heavy saucepan. Bring to a simmer, stirring until melted. Drizzle sauce over and around apples. Bake apples until tender, basting frequently with sauce, about 55 minutes. Arrange apples on plates. Place scoop of vanilla yogurt alongside. Drizzle sauce over and serve.